The object of this invention is the provision of a latching mechanism for closures for windows and doors that have turning or tilting closures. This invention is particularly concerned with a latching mechanism that is arranged on the hinge side of such windows and doors, which device is engaged in the closed position of the locked closure, but which must be disengaged for swing opening and tilt opening of the wing, as with any other latching mechanism. The invention provides for the engaging-and disengaging of the latching mechanism to take place automatically by the movement of the closure around its hinge axis. The invention has to do with a latching mechanism consisting of a fixed control cam and catch mounted to a fixed frame, and of a dog which is mounted on and movable with the closure relative to the frame.
The guidelines for window and door design provide that center closure latches must be added to the hinge sides of windows and doors as soon as the design length exceeds 1200 mm. These center closure latches prevent excessive bending of the closure frame relative to the frames which are anchored within the building walls, thus bringing about tightness of windows and doors.
The center closing latches for windows and doors are commonly engaged and disengaged by hand-lever drives with movable drive rods, through which the other functions of windows of doors are also accomplished, these functions being the locking and unlocking of the closure device, or the adjustment of the linkage axis for turn-and tilt opening of the wing. Fittings of this type have been made known through the German patent DE-AS No. 10 86 147.
In order that a prior art installation operate the hinge side center closure latching mechanism, it is necessary to provide corner tracks and these require installation space, which is not always readily available, particularly if the windows and doors are made from light metal-or hollow-plastic profiles, because the relatively small space between wing and fixed frame must also be used for the fittings for other functions.
The German patent DE-AS No. 11 93 833 shows the use of a latching mechanism for the necessary engagement and disengagement of a set-out latch for the turn-tilt opening of the closure. These are independent of the operating force working over a hand lever drive to the driving rods; that is, they work independently. This latching mechanism, however, is only engaged or disengaged during the opening and closing operation of the closure about its turning or vertical hinge axis; during the opening and closing operation around the horizontal or tilt axis of the closure, it does not operate at all. The operation of the latching mechanism is activated hereby in the area of the tilt axis by control cams and control areas, and is carried over to a place located far from the tilt axis in the vicinity of the upper horizontal closure edge. A closure-locking function, however, is not achieved, because of the necessary pressure between the closure and the fixed frame.
Austrian patent AT-PS No. 207 725 also shows a closure device with a turning linkage for the corners of windows and doors with turn-tilt closures. These work along the horizontal or tilt axis in oppositely-positioned upper horizontal groove areas of closure and frame. They are also dependent upon displacement movements of the closure about its hinge axis, opposite the fixed frame, by the coworking of a fixed control cam with a movable latch element. In that way the closure pressure generated by a corner drive and fixed frame, is carried over to the upper closure corner near the hinge axis of the closure without the use of a corner track. For the turn-joint side center closure between the closure and the fixed frame, however, a special pressure device is provided operated by a hand lever. The operation of this known corner closure device is based upon the fact that the latching movement is mainly brought out horizontally and is separately operated at the hinge axis and engaged with the center closure device.
German patent application No. P29 04 942.1 has a suggestion which is older and consists of the use of a control cam fixedly-mounted on the fixed frame and a movable dog mechanism guided on the closure, these being movable at a right angle to each other and exclusively by the movement of the closure around its hinge axis relative to the fixed frame. It is operated as a latching mechanism for automatic engagement and disengagement of center closures latches of windows and doors with turning and tilting closures wherein, the latching movement is connected to the corresponding joint axis of the nearest center closure device.
This type of latching mechanism for engaging-and disengaging centrally-located latches in latched position of the window or door, prevents an excessive bending of the closure struts relative to the struts anchored to the building walls. However, since the cooperating surfaces of the latch dog and latch catch of the centrally-located latches (according to the old solution) are formed with wedge surfaces opposite each other and sloped in the same direction, the optimum action effect of the center closure latches depends on an exact installation of all functional parts. Therefore, adjustments after installation of the functional parts cannot be completely eliminated.
A principle object of the present invention is the provision of a latching mechanism having improved operation and at the same time provides better mounting and post-installation adjustment. Therefore, the basis of this invention is a latching mechanism for engage-and disengaging of a latch on closures, especially centrally-located latches used with doors and windows of the described type.